1. Technical Field
The present invention relates to a semiconductor circuit, a driving circuit of an electro-optical device, and an electronic apparatus.
2. Related Art
A semiconductor circuit realizes complex functions by combining a plurality of circuit blocks. For example, a driving circuit for driving an electro-optical device, such as a liquid crystal display device or the like, has a plurality of circuit blocks divided among various functions. To each of the circuit blocks, a power supply voltage for operating circuit elements is supplied. The power supply voltages may be different depending on the circuit blocks.
Since the resistance of a power wiring line for supplying the power supply voltage is limited, if large current flows, a potential on the wiring line is temporarily changed. Further, if a current having a density equal to or more than a constant value flows in the power wiring line, the power wiring line may be disconnected due to Joule heat, migration, or the like, and the semiconductor circuit may be defective. The above-described problems can be avoided by increasing the width of the power wiring line and lowering the electrical resistance of the power wiring line and current density. However, if the width of the power wiring line is increased according to a maximum instantaneous current consumption value, the area of the semiconductor circuit is also increased by that amount.
JP-A-7-273635 suggests a method of controlling the width of the power wiring line by suppressing the maximum instantaneous current consumption of an output amplifier. JP-A-9-69569 suggests a method of optimizing the width of the power wiring line for a voltage which is different according to the circuit block.
The functions for which the semiconductor circuit is requested is complicated. For example, a driving circuit of an electro-optical device is accelerated and massive as an electro-optical device is enlarged with high definition. For this reason, it is necessary to further suppress the increase of the circuit area by keeping the width of the power wiring line to the necessary minimum, while preventing the power wiring line from being disconnected due to migration.